Effects Of Operating Parameters Research Articles

Numerical Research on Leakage Characteristics of Pure Hydrogen/Hydrogen-Blended Natural Gas in Medium- and Low-Pressure Buried Pipelines

To investigate the leakage characteristics of pure hydrogen and hydrogen-blended natural gas in medium- and low-pressure buried pipelines, this study establishes a three-dimensional leakage model based on Computational Fluid Dynamics (CFD). The leakage characteristics in terms of pressure, velocity, and concentration distribution are obtained, and the effects of operational parameters, ground hardening degree, and leakage parameters on hydrogen diffusion characteristics are analyzed. The results show that the first dangerous time (FDT) for hydrogen leakage is substantially shorter than for natural gas, emphasizing the need for timely leak detection and response. Increasing the hydrogen blending ratio accelerates the diffusion process and decreases the FDT, posing greater risks for pipeline safety. The influence of soil hardening on gas diffusion is also examined, revealing that harder soils can restrict gas dispersion, thereby increasing localized concentrations. Additionally, the relationship between gas leakage time and distance is determined, aiding in the optimal placement of gas sensors and prediction of leakage timing. To ensure the safe operation of hydrogen-blended natural gas pipelines, practical recommendations include optimizing pipeline operating conditions, improving leak detection systems, increasing pipeline burial depth, and selecting materials with higher resistance to hydrogen embrittlement. These measures can mitigate risks associated with hydrogen leakage and enhance the overall safety of the pipeline infrastructure.

Simulation of the synergistic effect of multiple operation parameters on cavity soliton in nonlinear fiber resonator

All optical soliton communication is a new generation of ultra-long distance and ultra-high speed optical fiber communication technology. Optical cavity solitons (CSs), whose pulse property is unique, have shown great potentials in optical soliton communication systems. Here, a theoretical model of nonlinear fiber resonator for CS generation is proposed. The effect of pump laser and resonant cavity parameters on the CS pulse performance is detailedly investigated and deeply analysed. Furthermore, the synergistic effect of continuous wave (CW) pump laser power and pump pulse peak power, and the synergistic effect of dispersion condition, fiber nonlinear coefficient and fiber length on the generation and property of CS pulse are respectively discussed and summarized. Finally, the launch conditions and parameter variation tolerances of cavity soliton in nonlinear fiber resonant cavity have been successfully generalized. These results can provide important instruction to the experimental generation and optimization of CS pulse.

Exergoeconomic assessment of a multi-section solar distiller coupled with solar air heater: Optimization and economic viability

This study focuses on optimizing the solar distiller and provides a foundation for future research and development in solar distillation technologies. This paper does an exergoeconomic analysis of a multi-section solar distiller (MS-SS) system that is combined with a solar air heater (SAH). Therefore, its objective is to determine the most effective operational and design parameters while taking into account the system's lifespan and interest rate. This will offer significant knowledge for improving the MS-SS. Key parameters examined in the study include exergoeconomic indicators, exergy production factor (EPF), exergy-based loss rate, exergy efficiency, and water cost. Variations in exergy loss rate across different seasons were observed, with implications for system efficiency. The exergoeconomic analysis demonstrates the impact of interest rates on the system's economic viability, with corresponding effects on water costs. The key findings suggest varying daily output and exergy efficiency, with the lowest values recorded in winter and the highest in summer. Summer demonstrates superior output exergy, averaging of 145 × 103 Wh per month. In the normal case of output salinity between 0 and 500 ppm, the cost was reduced by 96.7 %, and by 96.3 % in the case of four interior sections. Water cost reduction is also observable at the same output salinity, with 54.1 % at 0 ppm and 62.4 % at 200 ppm between number of interior sections = 0 and 4.

Effect of Operating Parameters on the Performance of Axially Rotating Horizontal Heat Pipe: Experimental Investigation

Effect of Operating Parameters on the Performance of Axially Rotating Horizontal Heat Pipe: Experimental Investigation

Unlocking the unique catalysts of CoTiO3/BiVO4@MIL-Fe(53) for improving Cr(VI) reduction and tetracycline degradation

Environmental contamination by hexavalent chromium (Cr(VI)) and antibiotic drug residues pose significant challenges to public health and ecosystems. This study investigates the application of CoTiO3/BiVO4@MIL-Fe(53) (CT/BV@Fe-MOF) for the reduction of Cr(VI) and degradation of tetracycline (TCL) under visible light. After grafting an iron-based metal–organic framework MIL-Fe(53) on a modified CoTiO3/BiVO4 composite, the photogenerated electrons could easily be transferred from CoTiO3 to BiVO4/Fe-MOF species via interfacial charge transfer. UV–vis diffuse reflectance spectroscopy showed that charge carriers were formed in response to visible light absorption. The effect of different operating parameters, including catalyst load, pH, initial Cr(VI), and TCL concentration, was systematically evaluated during the photocatalytic process. The CT/BV@Fe-MOF composite exhibited 98.7% reduction efficiency in Cr(VI) (50 ppm) and 97.5% degradation efficiency towards TCL (30 ppm) within 90 min, resulting in a greater efficiency than the pristine CoTiO3, BiVO4, and Fe-MOF materials. The CT/BV@Fe-MOF composite displayed excellent stability over six cycles, highlighting its potential for practical applications. In addition, the plausible degradation pathway of TCL was evaluated using LC-ESI/MS analysis, while the TEST program was utilized to investigate the toxicity of the products generated during the degradation process.

Analyzing the methanation thermodynamic feasibility of steel plant byproduct gases

To improve the utilization of byproduct gases in the steel plant, the coke oven gas (COG) methanation combined with blast furnace gas (BFG) and basic oxygen furnace gas (BOFG) was proposed in viewpoint of economy and environment. The optimization mathematics model based on Gibbs free energy minimization was established to predict the thermodynamic feasibility of the proposed methanation. To solve the proposed model, the convenient method was implemented by using the Gibbs module in Aspen Plus software. Effects of operation parameters on the methanation performance were revealed to identify the optimized conditions. To reduce the solid carbon concentration, it was found that the optimized conditions of temperature, pressure and stoichiometric number were 650 °C, 30 bar and 3.0, respectively. Moreover, it was discovered that 10 mol% of BFG or BOFG could be mixed into COG to obtain the maximum methane yield. In addition, it was testified that there were the good agreements between calculated results and industrial and published data, which indicated that the proposed methanation was thermodynamically feasible. Therefore, the simple and easy method was developed to evaluate the methanation operating conditions from the aspect of thermodynamic equilibrium, which provided the basic process conditions of byproduct gases methanation to enhance the steel plant efficiency and reduce carbon emissions.

Granulated graphene oxide-activated carbon for adsorptive removal of diclofenac sodium and ibuprofen in a continuous fixed-bed column

The granular graphene oxide-activated carbon (GGA) composite was synthesized with polyvinyl alcohol (PVA) and malonic acid (MA) as chemical crosslinker at different conditions. GGA synthesis was performed at different parameters including binder-to-powder ratio in the range of 0.5–1.2, synthesis time in the range of 2–24 h, and drying temperature in the range of 60–110 °C. Response surface methodology (RSM) was used to optimize the synthesis parameters of the adsorbent synthesis. The optimum parameters for synthesis were achieved at a binder-to-powder ratio of 0.875, a synthesis time of 23.992 h, and a drying temperature of 60.071 °C. XRD, FTIR, FE-SEM, BET and TGA analyses were used to discuss the characteristics of the adsorbent structures. The surface area and mechanical stability were found to be 156.59 m2/g and 95.417 %, respectively. The adsorption behavior of mono-components (diclofenac sodium (DCF)/ibuprofen (IBP)) and bi-components (DCF + IBP) on the GGA was evaluated in a fixed-bed column. The effects of column operating parameters, including bed mass (m: 0.25–0.75 g), flow rate (Q: 5–9 mL/min), and adsorbate concentration for DCF (C: 20–100 mg/L) and IBP (C: 5–15 mg/L) on the breakthrough curves were investigated. The experimental data of fixed-bed column were correlated with breakthrough models such as Thomas, Bohart-Adams, Yoon-Nelson, Yan, Gompertz, and Log-Gompertz via both linear (under different column operating conditions) and nonlinear (for DCF (Co of 60 mg/L; m of 0.5 g and Q of 7 mL/min) and IBP (Co of 10 mg/L; m of 0.5 g and Q of 7 mL/min)) regression analysis. The maximum adsorption capacities calculated by the Thomas model were 110.068 and 34.912 mg/g for DCF and IBP, respectively. In bi-component systems, antagonistic behavior was observed in the adsorption of DCF and IBP. The results showed that the GGA can successfully remove DCF and IBP through a fixed-bed adsorption column.

Community structure and function during periods of high performance and system upset in a full-scale mixed microalgal wastewater resource recovery facility

Microalgae have the potential to exceed current nutrient recovery limits from wastewater, enabling water resource recovery facilities (WRRFs) to achieve increasingly stringent effluent permits. The use of photobioreactors (PBRs) and the separation of hydraulic retention and solids residence time (HRT/SRT) further enables increased biomass in a reduced physical footprint while allowing operational parameters (e.g., SRT) to select for desired functional communities. However, as algal technology transitions to full-scale, there is a need to understand the effect of operational and environmental parameters on complex microbial dynamics among mixotrophic microalgae, bacterial groups, and pests (i.e., grazers and pathogens) and to implement robust process controls for stable long-term performance. Here, we examine a full-scale, intensive WRRF utilizing mixed microalgae for tertiary treatment in the US (EcoRecover, Clearas Water Recovery Inc.) during a nine-month monitoring campaign. We investigated the temporal variations in microbial community structure (18S and 16S rRNA genes), which revealed that stable system performance of the EcoRecover system was marked by a low-diversity microalgal community (DINVSIMPSON = 2.01) dominated by Scenedesmus sp. (MRA = 55 %-80 %) that achieved strict nutrient removal (effluent TP < 0.04 mg·L-1) and steady biomass concentration (TSSmonthly avg. = 400–700 mg·L−1). Operational variables including pH, alkalinity, and influent ammonium (NH4+), correlated positively (p < 0.05, method = Spearman) with algal community during stable performance. Further, the use of these parameters as operational controls along with N/P loading and SRT allowed for system recovery following upset events. Importantly, the presence or absence of bacterial nitrification did not directly impact algal system performance and overall nutrient recovery, but partial nitrification (potentially resulting from NO2− accumulation) inhibited algal growth and should be considered during long-term operation. The microalgal communities were also adversely affected by zooplankton grazers (ciliates, rotifers) and fungal parasites (Aphelidium), particularly during periods of upset when algal cultures were experiencing culture turnover or stress conditions (e.g., nitrogen limitation, elevated temperature). Overall, the active management of system operation in order to maintain healthy algal cultures and high biomass productivity can result in significant periods (>4 months) of stable system performance that achieve robust nutrient recovery, even in winter months in northern latitudes (WI, USA).

A facile strategy for designing hollow-porous polymer microparticles with tunable structures

Biodegradable hollow-porous microparticles have shown great potentials in chemical and biomedical areas owing to their distinctive structural attributes. Herein, a simple but instructive strategy was proposed to construct hollow-porous polylactic acid (PLA) microparticles in one-step based on electrohydrodynamic atomization technology. Hollow-porous microparticles with fusiform, red blood cell and spherical shapes were successfully fabricated with production rates of 70 mg/h, 30 mg/h and 105 mg/h. A formation map in terms of flow rate ratio and PLA concentration was obtained to demonstrate the operating regions. Effects of key operating parameters were studied, showing that high voltage (11.4 kV−12.4 kV) and low PLA concentration conditions (2.5 %−3.5 %) are preferred to get well-structured particles. The evolutions of Taylor cone and atomization state were also explored experimentally and numerically to further understand the process. The prepared microparticles exhibit excellent sustained release performance and high encapsulation rate (>90 %). This strategy offers a satisfactory one-step method for preparing various structured hollow-porous polymer particles as drug carriers.

Mechanical and surface properties of semifinished potato tuber exposed to UV-C radiation at varied operational parameters

The current study aimed at investigating the effect of certain operational parameters of UV-C radiator on the selected mechanical properties of semifinished potato tuber. Innovator potato variety was selected for the preparation of semifinished potato strips. The prepared potato strips were stored for 24 h following exposure at the desired storage condition. The irradiation experiment was carried out using a UV-C chamber at varied UV-C doses, Mode of exposure, and distance from the radiator. UV-C dose has a pronounced effect over the other tested parameters. Samples subjected at 60 mJ/cm2 resulted in higher resistance to compression and bending force while the resistance to cutting force was enhanced at a lower UV-C dose (15 mJ/cm2). Mechanical properties were not significantly impacted by the mode of exposure and distance from the light. Furthermore, the Morphological and microstructural properties of the sample were examined using SEM and AFM resulting in alteration in granule size, spacing, and roughness of the irradiated samples.

Dielectrophoretic separation/classification/focusing of microparticles using electrified lab-on-a-disc platforms

BackgroundSeparation, classification, and focusing of microparticles are essential issues in microfluidic devices that can be implemented in two categories: using labeling and label-free methods. Label-free methods differentiate microparticles based on their inherent properties, including size, density, shape, electrical conductivity/permittivity, and magnetic susceptibility. Dielectrophoresis is an advantageous label-free technique for this objective. Besides, centrifugal microfluidic devices exploit centrifugal forces to move liquid and particles. The simultaneous combination of dielectrophoretic and centrifugal forces exerted on microparticles still needs to be scrutinized more to predict their trajectories in such devices. ResultsAn integrated system utilizing two categories in microfluidics is proposed: dielectrophoretic manipulation of microparticles and centrifugal-driven microfluidics, followed by a numerical analysis. In this regard, we assumed a rectangular microchannel with internal unilateral planar electrodes equipped with three equal-sized outlets placed radially on a centrifugal platform where microparticles flow toward the disc's outer edge. The effect of different coordinate-based parameters, including radial and lateral distances (X and Y offsets)/tilting angles toward the radius direction (α), on the particles' movement was investigated. Additionally, the effect of operational parameters, including applied voltage, the microchannel width, the number of enabled electrodes, the diameter of particles, and the configuration of electrodes, were analyzed, and the distributions of particles toward the outlets were monitored. It was found that enhanced particle focusing becomes possible at lower rotation speeds and higher electric field values. Furthermore, the proposed centrifugal-DEP system's efficiency for classifying red blood cells/platelets and Live/Dead yeast cells systems was evaluated. SignificanceOur integrated system is introduced as a novel method for focusing and classifying various microparticles with no need for sheath flows, having the ability to conduct particles at desired routes and focusing width. Furthermore, the system effectively separates various bioparticles and offers ease of operation and high-efficiency throughput over conventional dielectrophoretic devices.

A Cold Flow Model of Interconnected Slurry Bubble Columns for Sorption-Enhanced Fischer–Tropsch Synthesis

For technical application with continuous operation of sorption-enhanced (SE) reactions, e.g., Fischer–Tropsch, a special reactor concept is required. SE processes are promising due to the negative effects of water on conversion and catalyst. The reactor concept of two interconnected slurry bubble columns combines the reaction with in situ water removal in the first, and sorbent regeneration in the second column with continuous exchange of slurry between the two. The liquid circulation rate (LCR) between the columns is studied in a cold flow model, measured by an ultrasonic sensor. The effects of different operating and geometric parameters, e.g., superficial gas velocity, liquid level and tube diameter on gas holdup and LCR are discussed and modelled via artificial intelligence methods, i.e., extremely randomized trees and neural networks. It was found that the LCR strongly depends on the gas holdup. The maximum of 4.28 L min−1 was reached with the highest exit, widest tube and highest superficial gas velocity of 0.15 m s−1. The influence of liquid level above the exit was marginal but water quality has to be considered. Both models offer predictions of the LCR with errors &lt; 6%. With an extension of the models, particle circulation can be studied in the future.

Membrane role in heat and mass transfer resistance distribution and performance of hollow fiber membrane contactor for SGMD desalination

Hollow fiber membrane contactor (HFMC) is the core device of heat mass exchange between seawater solution and sweeping air in sweeping gas membrane distillation (SGMD) desalination. In order to reveal the distribution of heat and mass transfer resistance on feed solution side, porous membrane side and sweeping air side, a mathematical model considering the simultaneous heat mass transfer and water vapor diffusion mechanism in the membrane pores was established for the cross-flow HFMC. The simulation results of the model were compared with experimental results and literature results. Comparison shows that the deviation of simulation results of the model is less than 13.4 %, which verifies the accuracy and reliability of the simulation results. Influences of the main structural characteristics of porous membrane on the resistance distribution of heat and mass transfer, efficiency and membrane flux were explored. Air side dominates the heat transfer process, while the membrane side accounts for less than 39 % of the total heat transfer resistance for the main range of membrane microstructure parameters investigated. The mass transfer is controlled by the porous membrane except for thin membrane with a thickness of less than 100 μm. Membranes with porosity above 0.8 and as thin as possible can achieve better mass transfer efficiency and freshwater flux. Increasing mean pore diameter has a strong promotion effect on the increase of membrane flux before it reaches 150 nm, and beyond this critical value, the water vapor diffusion mechanism changes from Knudsen collision to molecular collision. Effects of different operating parameters and membrane microstructure parameters on air temperature distribution and humidity distribution were also analyzed.

Local entropy generation optimization and thermodynamic irreversibility analysis of oval-shaped coaxial ground heat exchangers: A detailed numerical investigation

Optimizing the heat transfer and thermodynamic efficiency of Ground Heat Exchangers (GHE) is crucial for maximizing the energy efficiency of Ground-coupled Heat Pump (GCHP) systems utilized in building heating and cooling applications. This study pioneers an effective approach of both the first and second laws of thermodynamics of the newly oval-shaped coaxial GHEs (oval-CGHEs), assessing heat transfer, thermohydraulic performance, and local entropy generation rate to explore the optimum design and operational conditions for heat exchange maximization and entropy generation minimization. Utilizing a three-dimensional numerical model validated by experimental results, this study examines the trade-offs between heat transfer improvements and entropy generation rate intensification of the oval-CGHEs in comparison to the typical circular-shaped CGHE (circle-CGHE) further than exploring the effect of key operational and design parameters and performing sensitivity analysis. The results reveal that oval-CGHEs exhibit higher irreversibility as a penalty for their superior heat transfer capabilities compared to traditional circular-shaped CGHEs (circle-CGHE), which can be mitigated by optimizing the position of the inner tube. Moreover, the study underscores the criticality of maintaining a balance between enhanced heat transfer and the associated rise in irreversibility, particularly concerning the factors of mass flow rates and installation depths.

Evaporating crystallization effect of ammonium sulfate at atmospheric pressure under the action of ultrasound

Ultrasound enhanced evaporating crystallization has been proposed to solve the problems of low crystallization yield and uneven particle size in the evaporating crystallization process of ammonium sulfate solution at atmospheric pressure. The effects of key operating parameters, including the ultrasound power, stirring speed, pH value, and ultrasound time, on the yield of ammonium sulfate product and the duration of solid–liquid transformation time are studied. The results show that the ultrasound crystallization can increase the ammonium sulfate yield by 52.9 %, reduce the solid–liquid transformation time of ammonium sulfate by 10 %, and obtain ammonium sulfate products with higher crystallinity and more uniform particle size. Ultrasound promotes the crystallization of ammonium sulfate by enhancing the transfer of heat in the solution and reducing the supersolubility of the ammonium sulfate solution from 937.5 g/L to 833.33 g/L. This study provides experimental justification for the use of ultrasound in atmospheric evaporative crystallization.

High-efficiency ternary CeO2/WO3/AC photocatalyst supported by biomass waste-derived activated carbon for efficient doxycycline photodegradation: Optimization of synthesis conditions and operational parameters

Herein, a stable and reusable photocatalyst based on activated carbon (AC) with varying CeO2/WO3 loadings is synthesized and optimized using Central Composite Design (CCD) with the intention of Doxycycline (DOX) degrading as an organic pollutant. Prepared optimum photocatalyst have been characterized through XRD, BET, FE-SEM, EDS-Mapping, TEM, FT-IR, and UV–Vis band gap analyses. Additionally, the effect of operational parameters including catalyst dosage (0.2–1.4 g.L−1), DOX concentration (10–50 ppm), irradiation time (20–140 min), and pH (2–10) on DOX degradation is investigated by CCD in order to highly-efficient DOX degradation. The best working condition shows an experimental degradation efficiency of 97.23%. Moreover, selected CeO2/WO3/AC photocatalyst remove 83.11% of COD from DOX solution. The h+ and •O2− radicals are found to be essential for the destruction of the DOX due to heir strong and nonselective oxidation characteristics. Furthermore, the stability of the selected photocatalyst observed after undergoing five degradation cycles.

Evaluation of different operating parameters in the photocatalytic oxidative desulfurization process to degrade dibenzothiophene sulfur compound in the presence of BiOI/CeO2/NaY zeolite heterojunction

In this study, BiOI/CeO2/NaY zeolite composite was applied to remove sulfur compounds in gasoline model fuel to reduce environmental pollution and increase clean fuel production. First, the parent NaY zeolite was transformed into mesoporous zeolite during the sequential dealumination-desilication process. Then, the binary structures of BiOI/NaY zeolite and BiOI/Meso NaY zeolite were successfully synthesized by hydrothermal method. Next, in order to increase the photocatalytic performance in the desulfurization process, cerium ion was impregnated on the synthesized binary samples, so that the ternary combination of BiOI/CeO2/Meso NaY zeolite was investigated for the first time in the application of photocatalytic oxidative desulfurization in the presence of air as an oxidant. Furthermore, XRD, XPS, FT-IR, FE-SEM, EDS-MAP, TEM, BET, UV–vis DRS, PL and EIS analyzes were used to identify the structure, evaluate the compounds and determine the performance of the synthesized samples. In addition, the effect of operational parameters in the photocatalytic oxidative desulfurization process including photocatalyst dosage, model fuel concentration, reaction temperature, type of oxidant, type of extractant, the volume ratio of model fuel to extractant, different sulfur compounds, reusability and scavengers were assessed. The results showed that the BiOI/CeO2/Meso NaY zeolite ternary sample with an amount of 50 mg at the temperature of 25 ℃ and the concentration of 500 ppm of the sulfur compound was able to eliminate 98.8 % of the pollutant in 30 min. Moreover, the effect of the active species in the process was evaluated using various electron-removing agents to remove the sulfur compound from the fuel on an industrial scale.

Effect of surfactants (cetyl trimethyl ammonium-bromide, ethyl di-tetra amine and polyacrylamide) on the synthesis of zinc oxide for photocatalytic application

In this work, we report the effect of cetyl trimethyl ammonium bromide (CTAB), ethyl di-tetra amine (EDTA) and polyacrylamide as surfactants on synthesis of zinc oxide for photocatalytic application. The ZnO nanoparticles were synthesized with and without the surfactants and characterized using powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). In addition to this, the morphology of zinc oxide prepared in the absence and presence of these surfactants investigated through scanning electron microscopy (SEM). As confirmed from XRD and FTIR characterization results, the use of different surfactants did not affect the composition of ZnO nanomaterials. The photocatalytic activities were investigated by the degradation of methylene blue (MB) dye under sunlight irradiation. To optimize the effects of operational parameters, the study was carried out as a function of dye concentration, catalyst dose, and pH on the degradation efficiency of the photocatalysts. The optimum values of catalyst dose, dye concentration and pH of solution were found to be 0.09 g, 5 mg/L and 10, respectively. The ZnO nanomaterials prepared with CTAB surfactant showed highest degradation efficiency of 98% indicating potential application for practical decontamination of wastewater from toxic organic pollutants. KEY WORDS: Surfactants, Zinc oxide nanoparticles, Photocatalysis, Methylene blue Bull. Chem. Soc. Ethiop. 2024, 38(4), 923-935. DOI: https://dx.doi.org/10.4314/bcse.v38i4.9

Efficient removal of short-chain perfluoroalkyl substances (PFAS) using asymmetric membrane capacitive deionization

Concerns have been raised over the persistence and potential health risks of perfluoroalkyl substances (PFAS). PFAS pose significant challenges in water treatment owing to their chemical stability and the difficulty of treating them with conventional purification methods. Although traditional water treatment methods for contaminant removal have been explored, their effectiveness against PFAS remains limited. This gap in knowledge highlights the need for innovative approaches. This study introduces asymmetric membrane capacitive deionization (ACDI) as a novel method for short-chain PFAS removal to address the shortcomings of existing techniques. ACDI refers to a configuration in which an anion exchange membrane is removed from a conventional membrane capacitive deionization with both a cation exchange membrane and an anion exchange membrane. Among the PFAS, perfluorobutanesulfonic acid (PFBS), which is known to be difficult to remove because of its short chain, has been the focus. The ACDI system demonstrated superior deionization capacity (28.75 mg/g) and energy efficiency (energy consumption of 0.46 Wh/g) compared to conventional CDI and membrane CDI systems. In addition, the effects of key operating parameters, such as voltage (0.5 ∼ 1.2 V), initial concentration (50 ∼ 500 mg/L), and flow rate (1 ∼ 5 mL/min), on the PFBS removal were systematically investigated and superior at 1.2 V, 500 mg/L, and 2 mL/min. This study suggests the need for further exploration of real-world applications considering the presence of competing ions in wastewater. This study provides valuable insights into advancing CDI technology for the sustainable treatment of industrial wastewater containing PFAS.

Large eddy simulation for jet noise characteristics of liquid rocket engine with guide groove

The study of jet noise characteristics of liquid rocket engines is a prerequisite for evaluating the noise level of rockets and effectively controlling the noise. To obtain the effect of engine operating and structural parameters on jet noise, the Large Eddy Simulation combined with the FW-H integration method is applied for the scaled engine with guide groove under different chamber pressures and nozzle expansion ratios. The simulation results show that the noise field distribution of the jet with a guide groove is highly symmetrical and has obvious directivity. The noise caused by jet impingement on the guide groove is strongly correlated to the distribution of high vorticity regions. Remarkably, higher chamber pressure leads to longer potential jet length, higher noise sound pressure levels, and greater enhancement effect of impact on noise. However, the frequency spectral characteristics are basically invariant. When the chamber pressure is constant, the increment of the nozzle expansion ratio in a certain range results in lower noise peak frequency and weaker impact effect.